phy: starfive: make phys depend on HAS_IOMEM

the startfive phy drivers use devm_platform_ioremap_resource() which on
some archs (s390) is not present. So make the drivers depend on HAS_IOMEM

Fixes: f8aa6608

 ("phy: starfive: Add mipi dphy rx support")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202307250509.oeudxG28-lkp@intel.com/
Reviewed-by: Changhuang Liang <changhuang.liang@starfivetech.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20230725063856.482696-1-vkoul@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>